Accident Narrative
The pilot's father had recently purchased the airplane for his daughter, who was receiving model-specific training from a contract flight instructor. Her former flight instructor was also aboard as a passenger. During pre-flight procedures, the engines were started and subsequently quit. After restarting, they quit again. The engines were started a third time, and the airplane was taxied for takeoff. Shortly after beginning the takeoff roll, the pilot reported an unspecified engine problem. The airplane then drifted across the median and a parallel runway, rolled abruptly to the right, struck the ground, and cartwheeled. The landing gear was extended, and neither propeller was feathered.
Engine Examination
Disassembly and examination of the right engine and turbocharger revealed no anomalies. However, disassembly and examination of the left engine and turbocharger identified that the mixture shaft and throttle valve in the throttle and fuel control assembly were jammed in the idle cutoff and idle rpm positions, respectively. Flow tests conducted on the manifold valve and fuel injector lines produced higher-than-normal pressures, indicating a flow restriction. Further disassembly of the manifold valve revealed that the needle valve in the plunger assembly was stuck in the full open position, which had collapsed the needle valve spring. A scribe was used to free the needle valve, after which repeated flow tests on the manifold valve and fuel injector lines resulted in lower pressure. Plunger disassembly showed that threads had been tapped inside the retainer, and metal shavings were found between the retainer and spring. Notably, the Teledyne Continental Motor (TCM) retainer has no threads.
Performance Data
GPS data indicated that from the start of the takeoff roll to the attainment of rotation speed, the airplane covered 2,698 feet. The maximum speed attained was 132 mph. Computations showed that the distance to clear a 50-foot obstacle was 2,000 feet, the distance to clear a 50-foot obstacle on a single engine was 2,600 feet, and the accelerate-stop distance was 3,000 feet.